Air painting device



J. A. PAASQHE AIR PAINTING DEVICE Filed July 19,' 195o Patented AMay 19, 1936 UNITED STATES PATENT OFFICE 2,041,482 Ara mimmo -nrzvrcn Jens A. Panache, warmem, m".

Application July 19, 1930, Serial No. 469,036

13 Claims.

The invention relates generally to air painting devices and more particularly has reference to devices of this nature adapted to be 'operated by air under pressure.

Oneiof the objects of the invention is to provide a novel device of this character capable of being operated by air under comparatively low pressure.

Another object of the invention is to provide. in a device of this nature, a novel means for controlling the character oi' the spray' stream delivered thereby.

In connection .with the foregoing, another object of the invention is to provide a novel means for gradually varying the proportion of pressure iiuid to liquid whereby to effect a change in the nature oi the spray discharged from the device.

Another object resides in the provision-oi' a i 30 novel control means by which the surface area covered by the spray, for any given distance 'between said surface and the device, may be readily varied by the operator.

The invention further contemplates the provision of a device in which a single manually actuated member controls the graduation of the spray between the limits oi a line mist-like spray and a heavy coarse spray, proportionally alters the size of the spray to vary the surface area covered thereby.

Still another object of the invention resides in the provision of an improved means for controlling the ilow of pressure i'iuid to the device. A further object is to provide a novel control mechanism which embodies the combination of a valve for normally preventing most but not all of the flow of pressure 'fluid to the device and means for causing a back-pressure in said flow to prevent the flow of liquid to the device.

Another object of lthe invention is to provide a device in which the parts are so arranged that disassembly thereof may be easily accomplished to permit cleansing, replacement, or inspection oi the parts.'

45 A further object resides in the provision oi a novel container for the iiuid to be sprayed including a simple means for preventing the entrance of foreign matter into the fluid line.

` In the drawing:

Figure 1 is a side elevation on a reduced scale loi' a device embodying the invention.

Fig. 2 is a fragmentary vertical section taken centrally and longitudinally of the device.

Fig. 3 is a horizontal section on an enlarged and at the same time scale of the front end of the device taken substantially on the lines 3-3 of Fig. 2. n, Fig. 4 is a detail section oi the top of the liquid supply reservoir. 1

Figs. 5, 6 and 7 respectively are diagrammatic 5 views showing successive operative results produced by variable actuation of the control means.

Fig. 8 is a view similar to Fig. 5 showing another type of spray.

Fig. 9 is a. transverse section through the front end of the device as indicated by the line 9--9 oi Fig. 2.

Fig. 10 is a transverse section through the control valve taken substantially on the line I--Ili of Fig. 2. l

In its broad aspect, the invention contemplates an organization adapted to be connected to and operated by a source of pressure-fluid under low pressure. A portion of said pressure-fluid is utilized to feed the liquid to be atomized or vaporized to a mixing chamber wherein it is broken up by the pressure fluid. Control means, associated with the mixing chamber, is arranged to vary the proportion of pressure iluid to liquid over a wide range so that the character of the resulting spray produced may be likewise varied. 'I'his variation of character ranges gradually from a very finely atomized spray to a heavy coarse spray, thus producing a. device capable of performing many different types of work.

The same control means is further adapted to alter the dimensions of the spray whereby to vary the surface area covered thereby. The range in this case is from a small area when the line spray is produced to a large area when the coarse spray is discharged. A single manually actuated op-1 erating member governs the entire manipulation of the device including the admission oi' air, the flow of liquid, and the actuation of the control means.

For purposes oi' disclosure, the present embodiment of the invention is shown as being particu# larly adapted for atomizing paint or other coating material by air under low pressure. It is recognized, however, that the device is capable -of vaporlzing liquids, other than paint, by pressure fluids, other than air, and it is contemplated that all such modied uses will fall within the spirit and scope of the appended claims.

In the embodiment of the invention which has been selected for the purpose of illustration, the body of the spraying device comprises -a barrel having ysecured thereto a handle 2l which may be of the pistol-grip type. The forward end of the barrel, which is the left-hand end of the de- 55 vice as illustrated, tsl: pers gently toward the axis of the barrel. Withiri this tapering portion is an axially extending borne 22 (Figs. 2, 3 and 9) which is cylindrical in sha'ple and terminates at an inwardly extending slnoulder 23. Preferably, the shoulder 23 is formeel as a part of the barrel and is annular to define :a port 24 at the rear end of the bore through which pressure fluid is delivered as will be presently described.

A nozzle member- .25, from which the liquid to be atomized is discharged, is adapted to be received and supported in the bore 22. As shown, the liquid nozzle member comprises an elongated, substantially cylindrical plug fashioned to nt l5 snugly into said bore. A stop shoulder 2S (Figs.

2 and 3) within the bore engages the inner end of said member to space it a short distance from the annular shoulder 23. The outer end of the member tapers gently as indicated at 25, to a relatively blunt point, which projects slightly beyond thefront end of the barrel 20. The nozzle member is provided with an axial bore 21 extending from the tapered end to a point within the member. At its inner end, the bore communi- Cates with a laterally opening port 28.

While the fluid Or liquid t0 be atcmized and sprayed may be delivered to the bore 21 in many ways, the illustrated organization is especially .uitable for a device by which color or paint is applied, The lower side of the barrel 2D, near the rear end of the tapered portion, is provided with an aperture 30 of vsubstantial size which communicates with the bore 22 in the barrel. A tubular conduit 3l is rigidly secured at one end to the barrel and connects the aperture 30 with a source of liquid.

The source of liquid, in this instance, is a closed, air-tight receptacle indicated generally at 32 (Fig. l) comprising a cup-shaped lower section 33 (Fig. 4) and a cover element 34. For convenience, the cover element 34 is mounted rigidly on the conduit 3i in any suitable manner as by providing a shoulder 35 (Fig. l) on the conduit against which the cover is held in air-tight relation by a nut 3B screw threaded on the end of the conduit. The lower section 33 is arranged to be detachably secured to the cover element by means of a quickly releasable clamping device. This device comprises an elongated lever 31 (Fig.

5o 4) pivotally mounted, as at 38, on the cover, which lever at one end isformed as a hook 40 arranged to extend around the edge of the cover element 34 into engagement with an outwardly projecting head 4I on the lower section 33. The

lever 31 carries a second hook 42 adapted to engage the head 4I on the opposite side of the lower section. The hooks are actuated by an eccentrically pivoted finger piece 43 so interposed between the lever 31 and the hook 42 that a o0 force may be exerted on the hooks 40 and 42 to draw the cover element and the lower section of the receptacle tightly together. A gasket 44, carried by the cover element, is provided to insure an air-tight seal between the sections of the re- 5 receptacle.

The liquid in the liquid nozzle municating with the receptacle is conducted to member 25 by a tube 46 comthe port 28 in said member.

Preferably, the tube is screw-threaded into theV 79 member to facilitate disassembly for cleansing purposes. The tube extends from the member through the aperture 30-in the barrel and into the receptacle 32 through the conduit 3i. The tube, as may be seen in Fig. 2 is of substantially less diameter than the conduit and is Substantially straight.

The conduit, however, curves slightly forward so that when assembled the tube will engage opposite sides of the conduit. This relationship holds the tube rigidly Within the conduit and further serves to prevent movement of the liquid nozzle member relative to the barrel.

The lower end of the tube terminates near the bottom of the receptacle and is enclosed by a coaxially arranged, cylindrically-shaped foraininous member 41 (Fig. l). The foraminous member serves as a strainer to prevent the entrance of foreign matter to the tube. The cylindrical shape of the member is advantageous in that in use the member is vertical and any foreign matter will tend to settle to the bottom of the receptacle thus allowing an uninterrupted flow of liquid through the upper part of the member to the tube.

Referring particularly to Figs. 2 and 3, 50 indicates generally a spray nozzle from which the atornized spray is discharged. The spray nozzle comprises a head portion 5I rounded on one side and provided with an axially extending tubular shell 52 projecting from the opposite side thereof. The. outer diameter of the shell is slightly less than the inner diameter of the bore 22 so that the shell may extend snugly and slidably into the bore. The front end of the liquid nozzle member 25 is recessed or annularly grooved,

as at 53 (F'ig. 2), to a depth approximately equal to the thickness of the shell to permit sliding movement of the shell between the front end of .the liquid nozzle member 25 and the barrel 20 (see 9).

The head portion 5I has an axial discharge orifice. or aperture extending therethrough, which has a particular formation in thisembodlment for the purpose of controlling the finely atcmized Spray discharged therefrom. Thus, that portion of the orice which communicates with the interior of the shell flares inwardly, as at 54 (Fig. S) to form the complement of the tapered point 25a of the liquid nozzle member 25. The largest diameter of the flared portion of the orifice is less than the inner diameter of the shell, thus providing an annular shoulder 55 between the orifice and the shell interior. The f'ront end of the flared portion communicates with a short bore 56 of constant diameter which extends nearly through the head where lt meets a narrow slot-like kerf 51 formed in the front face of the head.

The interior of the shell 52, the flaring portion 54 in the head, and the front surface 25* of the liquid nozzle member 25, define therebetween a mixing chamber or compartment, designated 58, in which, since the spray nozzle 50 is -movable relative to the liquid nozzle member 25, the relative positions of the parts may be varied to perfectly control the flow of liquid to the discharge orifice.

'Ihe pressure fluid by which the liquid is vaporized as it issues from the liquid nozzle member 25, is admitted to the device in the following manner: The rear end of the barrel 20 isclosed by means of a plug 6D (Fig. 2) soldered or otherwise rigidly secured to the barrel. Externally, theA end of the barrel is screw-threaded to receive a hollow cap 6| which is somewhat elongated and is, in turn, externally screw-threaded to receive a gland 63. A flexible conduit 64 of any wellknown construction is carried by the' gland to connect the interior of the cap with a source of pressure iiuid (not shown).

The passage of pressure fluid through the cap 6| is controlled by a valve mechanism. To this end, the cap intermediate the ends thereof is provided with an inwardly extending. annular shoulder 65 fashioned to form a valve seat. A valve member 66 having a tapered outer surface 61, is normally urged into engagement with the valve scat by a spring 68 which is seated on the valve member about a small boss 69 formed integrally with said member. The other end of the spring bears against a hollow plug 16 screwthreaded into the outer end of the cap 6|.

The means for actuating the valve manually comprises a trigger element 1|., pivotally mounted as at 12, within the barrel. The trigger extends from the barrel in front of the handle 2| in such manner that it may be readily manipulated by the index finger of the operator. Within the barrel, the trigger carries a U-shaped member 18 arranged to form a rearwardly opening pocket. A longitudinally extending link 14 has one end seated in the pocket, and the other end is conan elongated boss 16 formed integrally therewith to provide a greater bearing surface for the pin.

The free end 11 of the pin is of reduced diameter and extends through the valve, opening formed by the annular shoulder 65 into an axial recess 16 in the valve member 66. This arrangement is advantageous in that there is no positive connection between the valve and the actuating means thereby permitting the valve member to adjust itself freely to the seat when released by the pin 15.

Pressure uid is conveyed through the barrel by a conduit 86 secured at one end in an aperture in the plug 60 and at the other end in the aperture 24 formed'by the annular shoulder 23. From this point, the pressure fluid is conducted to the mixing chamber 58 and at the same time a portion thereof is diverted or by-passed to the upper part of the receptacle 32 to produce a feeding of the liquid under pressure.

A simple and effective manner of accomplishing this result is by providing one or more passageways between the front and rear ends of the liquid nozzle member 25, which passageways communicate with the conduit 3| leading to the receptacle. For this purpose, opposed transverse sides of the liquid nozzle member 25 are flattened, as at 8| (Fig. 3), by cutting away portions thereof. Passageways 82 are thus defined between the member 25 and the sides of the bore 22. The depth of the passageways is such that the passageways communicate with the aperture 30 in. the barrel and, vat the front end of the liquid nozzle member 25, permit, the passage of pressure fluid past the portion of the shell 52 surrounding the member 25 to discharge into the mixing chamber 58.

In outlining the operation of the device, it should flrst'be mentioned that the adjustment of position of the spray nozzle 56, relative to the' liquid nozzle member 2E, is effected by the trig ger member 1l. In the normal relation of parts, the shoulder 55 in the spray nozzle is spaced a short distance forwardly of the end of the liquid nozzle member 25. A link 83 (Figs. 1 and 2) is pivoted, as at 84, to the trigger member 1| and extends forwardly therefrom beneath the barrel. The front end of the link carries a yoke portion 85 arranged to straddle the conduit 3| and the front end of the barrel, and the ends of the yoke are bent toward each other to engage diametrically opposed sockets 86 formed in the head of the spray nozzle. Hence, manipulation of the trigger member to open the valve produces a simultaneous rearward movement of the spray nozzle 56 toward the liquid nozzle member and the extreme limit of such rearward movement is determined by the engagement of the complementary tapered surfaces 54 and 25e.

The entire operation of the device is con- 1o trolled solely by the manipulation of the trigger member 1|. That is to say, the character of the spray which will be discharged from the device,I as well as the area of the surface which will be covered by the spray for any given distance l5 of the device from said surface, may be controlled by moving the trigger member through varying distances.

Considering that the device is in its normal position and is ready for use, it will first be presumed that the trigger is retracted a very short distance. This operation unseats the valve member 66 and allows pressure fluid to ilow through the tube 86, passageways 82, and into the mixing chamber 58. At the same time', a 25 part of the pressure fluid is diverted into the receptacle through the conduit 3| and applies pressure to the surface of the liquid therein. I'his initial movement of the trigger has caused the spray nozzle` 50 to move slightly toward the 30 liquid nozzle member 25 but such movement is not suiiicient to carry the shoulder 55 in the spray nozzle past the discharge end of the liquid nozzle member. Consequently, a back pressure is built up in the mixing chamber which is ample to prevent the flow of any liquid from the receptacle. Obviously, since the discharge orifice from the spray nozzle is open a certain amount of pressure fluid escapes therefrom 'during this time and this escaping pressure fluid may, if desired, be utilized by the operator to cleanse or dust the surface to be sprayed.

Continued movement of-the trigger member does not have any further effect upon the valve 66 since the valve is alreadyy open, but does produce a retraction of the spray nozzle toward the liquid` nozzle member. This continued retraction gradually decreases the volume of the mixing chamber 58 and diminishes the amount of backpressure in the mixng chamber until the end. of the liquid nozzle passes the shoulder 55 in the spray nozzle. At about this position of the parts, the back pressure has decreased to such a point that the pressure in the receptacle 32 causes a flow of liquid through the tube 46 55 and bore 21. This liquid is discharged into the tapered part 54 of the discharge orifice, where it is mixed with and atomized by the pressure fluid. Since the volume of pressure fluid at this time is relatively large, as compared to the volume 60 of liquid atomized thereby, the resulting spray discharged by the device will be in the form of a very fine, smoke-like mist. l

As the complementary tapered surfaces 25 and 54 are brought closer together, it` will be ap- G5 parent that the tapered space therebetween decreases in aggregate cross-sectional area and gradually restricts the amount of pressure fluid flowing therethrough. As a result. the back pressure of the pressure i'luid decreases to effect the 70 flow of an increasingly greater quantity o f lion'd. This variation of the proportions of pressure fluid and liquid alters the character of the discharged spay, in that the particles of liquid in the spray become heavier until a coarse spray, well adapted 75 for producing a rough or ilne stipple effect, results.

the spray nozzle.

The tendency toward an injector action, caused by the pressure-fluid passing the liquid nozzle f member, probably does not materially effect the amount oi liquid discharged. 'Ihis may be due to the fact that the cross-sectional area of the most restricted part of the discharge orice (which is the bore 56) is positioned in front oi the end of the liquid nozzle member and is less than the effective area of the tapered pressureiiuid passageway leading thereto. Hence, there will be a greater or lesser amount of back pressure acting upon the liquid up to the point at which the aggregate cross sectional area oi the tapered pressure-fluid passageway becomes equal to the cross-sectional area of said restricted part 56 of the oriiice. Further restriction ofthis tapered passageway area will probably produce an injector action whichwill additionally increase the ow of liquid to some extent.

In the operation of the device which has just been described, it has been considered that the device was attached to a source of pressure iluid (not shown) which is in the nature of a pressure tank or similar well-known instrumentality embodying a safety valve or automatic pressure release. In such a case, the valve 66 may completely close the pressure fluid conduit. In certain uses of the present invention, however, it may be found desirable to connect the spraying device directly to an air compressor unit which is constantly running and which does not embody means for preventing the pressure behind the valve from building up. The present invention is arranged to prevent th`e accumulation or building-up of such excess pressure.

To this end, with particular reference to Fig. 10, the valve member 'S6 is fashioned to allow a leakage of air between the valve surface 61 and the valve seat 65 when the valve is in its normally closed position. One manner of accomplishing this is by slightly recessing opposed sides of the valve surface 61, as in indicated at 61B. The escape of the pressure iluid through the valve prevents the accumulation of pressure uid behind the valve, even though the air compressor unit,

to which the device is attached, is constantly op-4 erating. Such escaping pressure iluid passes through the tube 80. passageways 82, and into the mixing chamber 58 where back pressure is created in the manner which has been previously described to prevent a ilow of liquid to the mixing chamber. Obviously, the pressure iluid ultimately discharges from the device through the discharge orifice.

The variation of the size of the area covered by the spray is also a direct result of the manipulation of the trigger member. With reference to Figs, 5, 6 and 7, three consecutive positions of the spray nozzle 50 are shown. As the trigger is initiaily moved a small jet of air is released as is shown in dotted outline centrally of the fanshaped spray illustrated in Fig. 5. Further movement of the trigger moves the spray nozzle to the position at which the ne, mist-like spray is produced. In this position, the surface area effectively covered by the spray is relatively small as indicated at- A. In Fig. 6, an intermediate position of the spray nozzle is shown in which the spray stream is heavier and a larger surface area.

B is effectively covered. In Fig. '7, the spray nozzle is completely retracted to produce the heaviest spray and to effectively cover a maximum oi surface area, as shown at C.

Figs. 5, 6 and 'l show the spray in the shape of a fan, which shape is produced by the narrow ker'f 51. Obviously, sprays of diierent shapes may be produced by varying the form of the nozzle, as, for example, the conical stream D (Fig. 8) which is produced by providing a shallow arcuate recess 89 in the outer face of the spray nozzle.

The movable relationship of the spray nozzle and the liquid nozzle member, and the complementary tapered surfaces therein, constitutes the control means which permits the device to be operated at low pressure. This results from the provision of what may be termed a force feed for the liquid and a control of the volume of liquid fed by the creation of back pressure or resistance to ow which is variable.

Preferably, means are provided for adjusting the device to produce a spray of constant character. In the present instance, this is accomplished by adjustably limiting the extent of retraction of the trigger member. Thus, a split taper sleeve 90 (Figs. l and 2) encircles the barrel 20 intermediate the handle 2| and the trigger member 1|. The sleeve is of graduated width and is rotatable on the barrel to interpose prtions of various widths in the path of retraction of the trigger. This arrangement enables the operator accurately to limit the extent of movement of the trigger member, and if desired, positively to lock the trigger against accidental movement.

From the foregoing, it will be aparent that a spraying device has been provided which is exceedingly simple in operation and' by'which an operator can produce a spray suitable for substantially any kind ci work. Moreover, the device is simple in its constructional details and may be readily taken apartI for cleansing purposes or for replacement of parts.

I claim as my invention:

1. A spraying device comprising, in combination, a barrel having an axial recess at one end, a source of pressure iiuid connected to said recess, a valve controlling the passage of uid to said recess, a nozzle element iitted in said recess, said element having an axial bore extending inwardly from the outer end thereof, a conduit connecting said bore and a. closed liquid receptacle, means providing longitudinal passageways for pressure fluid between said element and the walls of said recess, a pressure conduit connecting said passageways and said receptacle, a spray nozzle having a discharge orifice therein mounted on said nozzle element for movement toward and away from the outer end of said bore, said spray nozzle being internally recessed t0 provide a pressure fluid and liquid mixing chamber, and a single manually operated means for controlling said valve and varying the position of said spray nozzle.

2. A spraying device comprising, in combination, a. barrel having a liquid discharge nozzle at one end, a source oi liquid connected to said nozzle, an apertured member enclosing said nozzle in spaced relation thereto to provide a mixing chamber therebetween, adjusting means for moving said member and said nozzle relatively, a source of pressure fiuid, a conduit connecting said source of pressure fluid With said mixing chamberl a by-pass conduit interposed between accises 5 said source oi liquid and said pressure iluid condiu't, a valve controlling the passage of pressure duid through said pressure :duid conduit and said bynpass conduit, and actuating means con nc'cted to said valve and to said apertured mem= oer for simultaneously actuating said valve and said adjusting means.

3. in a spraying device, the combination of a barrel having a recess at one end, a nozzle element in said recess, a conduit secured to said barrel and commimicatins with said recess, a liquid reservoir connected to said conduit, said nozzle element having a bore therein, and a liquid conduit connected to said bore and eztending :from said barrel through said rst mentioned conduit.

nl a Spraying device, the combinano of a barrel having a liquid nozzle loosely mounted in l one end thereof, a sourcen of fluid, a conduit conneoting said source to said nozzle, and means engaged by said conduit to prevent movement of seid nozzle relative to said barrel.

5. in a spraying device, the combination of a barrel having a discharge nozzle loosely mounted in one end thereof. an elongated conduit having a screw threaded connection with said nozzle, said barrel having an aperture therein through which. said conduit extends and which said conduit engages to hold said nozzle in said barrel.

' o'. 'in a spraying device, the combination of an adjustable spray discharging member having a hollow chamber therein, means for introducing liquid under pressure to said chamber, means for introducing pressure iiuid to said chamber, said member having control means therein `operable to create an internal pressureivithin said chainber for resisting the i'iow oi liquid, the amount oi said internal pressure so created being dependent directly upon the position ci adjustment oi said discharging member, and e. single manipulable for con.trollbor,7 the introduction ci pres sure duid and the adjustment of said. discharging member.

i. .d spraying device comprising. in combinay tion, o.. barrel having an axial recess in one end; a nozzle having an outwardly opening axial bore therein loosely mounted in said recess, a conduit connecting,r said bore with a source of liquid and serving to secure said nozzle in operative position, and a pressure-duid conduit communicating with. said recess in said barrel, said barrel and said. nozzle having clearance therebetween to provide a passageway for pressure iiuid.

il. .s spraying device comprising1n combinan' tion, a barrel having an atrial recess in one end, a nozzle having an outwardly opening axial bore therein detachabiy mounted in said recess, a conduit connecting said bore with al source ci liquid, a pressureuid conduit communicating said recess in said barrel, said nozzle being longitudinally cut away on opposite sides to forni passageways for pressure :duid from said pres sureoluid conduit through the recessed part of said barrel, and a pressure-fluid by-pass come municating with said eut-away passageway and connected with the source of liquid.

e. in a spraying device, the combination of a spray nozzle, means :for delivering pressure uld to said nozzle, a valve controlling the new of pressure iluid, a penently open conduit for delivering material to be sprayed to said nozzle, sus for citt-acting a iiow oi material tlu'ough said conduit under pressure, adjustable means for controlling the new of material by op uid pressure, and a single manually operated instrumentality for actuating said valve and manipulating said adjustable means.

i0. In a spraying device, the combination of a substantially cylindrical liquid nozzle member, an apertured spray nozzle member having a tubu lar portion siidable over the end of said liquid nozzle member, a pressure fluid source connected with the device, control means for governing the pressure fluid iiow, means providing a pressure fluid' passageway discharging between said two nozzle members, and manually operable means responsive to the operators manipulations for' actuating said controlling means and adapted for slidably moving said two members axially with respect to each other when said controlling means is in position to permit pressure fluid flow, said nozzle members having a complementary interfitting relationship operable to vary the pressure exerted therebetween by the pressure fluid.

l1. lin a device of the character described, relatively movable spray and liquid nozzle members, a pressure iiuid passage communicating with said spray nozzle, a valve for controlling the flow of pressure iiuid through said passage, a source of liquid connected with said liquid nozzle member, means providing a chamber about the end of said liquid nozzle member and communicating with said pressure iiuid passage, means providing communication between said pressure fluid passage and said source of liquid for conveying to said source pressure iiuid under substantially the same pressure as in said chamber, and control means for opening said valve and for relativelymoving said nozzle members, said control means being arranged to open said valve before moving said nozzle members, whereby uid pressure is developed in said chamber and upon said liquid before said nozzle members are relatively moved.

i2. In a device of the character described, relatively movable spray and liquid nozzle members, a pressure uid passage coxnxnunicatingv with said spray nozzle, a valve for controlling the ilow of pressure uid throughsaid passage, means providing a chamber about the end of said liquid nozzle member and communicating with said pressure iluid passage, means for delivering liquid to said liquid nozzle member under substantially the same pressure as the pressure in said chamber, and coen movable control means for opening7 said valve and for relatively moving said spray nozzle, said control. means being arranged to open said valve fully during initial movement and being adapted to maintain said valve open continuously while beine moved through minute Idegrees to relatively move said nozzle members.

i3. in a spraying device including a body movable to direct he device toward a surface to be sprayed, cooperative spray head and nozzle members mounted for relative axial rnovement, pres sure huid and spray material sources communieating with said head and nozzle, a pressure responsive actuating member connected with said' head and adapted for moving the same from an initial position toward said nozzle for varying 

